Openbanking should be the priority and immediately after that openstockbrokering too
As of now people don't have their savings in USD and their investments in SP500 but in [bank of choice]USD and in [broker of choice]SP500
This means that outage or one of the usual dumb flagging that make banks stop providing you services until you send them an x-ray of your colon could potentially leave you without spendable money even if you have a million dollars or more